Dry gas-meter.



L. B. GAWTRY.

DRY GAS METER.

APPLICATION FILED DEO.13,1912.

1,070,679, Patented Aug. 19, 1913.

' Zense Y Iwner srmmm f *ojxj. 5/90/19 7 UNTTED STATES PATENT @FFTBE.

LEWIS 1B. GAWTRY, OF NEW YORK, N. Y.

mar GAS-METER.

Application filed December R3, 15912.

To all whom it may concern:

Be it known that I, LEwIs B. GAWTRY, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Dry Gas Meters, ofwhich the following is a specification. i

The invention relates to dry gas meters of the type wherein the gasisadmitted to a chamber of known'capacity and in bellows form, whichchamber in expanding and contracting actuates suitable indicatingmechanism.

The invention consists in constructing the bellows with a flexible wallimpervious to.

gas on its inner side but on its outer side,

spongy and absorptive of oil, so that through Fig. 5 is anenlarged viewin section of a portion of the flexible wall, supporting rings,diaphragms and meter casing.

Similar letters of reference indicate like parts.

As ordinarily constructed, the bellows or working chamber of a dry gasmeter comprises two metal diaphragms A, B, secured in rings C. D. Theflexible peripheral wall E of the bellows has its ends securedtogether-at F, and is attached at its edges to the diaphragms A, B.Before the band is put in place itis usually stretched over an annularformer, so as to give it an outward bulge or fold G. Une of thediaphragms, as A, is free to move, so that when the gas under pressureenters the bellows and expands the same, the band tends to flatten,

and when the gas escapes it'resumes itsoriginal shape.

The material of the flexible Wall is usually leather of such closenessof texture as willrender, it impervious to gas under pressure. For thisreason and also because the Wall must be soft and pliable so as to offeronly a negligible resistance'to the movement of the Specification ofLetters Patent.

Patented Aug. 31 $1 13 911.3.

Serial no. 736.464.

free diaphragm by the entering gas, the heavier or thicker leathers,such as oX-hide or calf-skin are not suitable, and thereforesheep-skinis generally found best adapted to the purpose. In order tomaintain the impervious quality by filling the pores which exist, andalso to insure the desired flexibility even of sheep-skin, it isnecessary to keep the leather saturated with oil, usually a goodlubricating oil; otherwise the leather dries and hardens, thus impairingthe sensitiveness of the chamber in yielding to the gas pressure, andhence its accuracy as a measuring device, and, in time, owing to theconstant opening and closing of the fold G, the leather itself cracks,thus causing leaks which result in incorrect registration, thusdestroying the utility of the meter.

For many reasons it is not practicable to oil the leather beforesecuring it in place as a part of the bellows. Because of. its necessary thinness, oiling renders it soft and slippery, so that handling ofwhole skins thus treated is difiicult and troublesome, nor can bands cutfrom the skins be oiled prior to being attached to the diaphragm rings.lin order to make gas tight joints, each edge of the band is secured tothe rings by a wrapping of strong cord H put on tightly, and thencovered with an impervious coating of hard varnish or shellac. @ilsoaked into the pores cannot be wholly driven out by pressure, althoughit will in time evaporate. Hence if the band be previously saturated,the joint becomes pervious to gas. So also the protective coating ofvarnish or shellac cannot be made properly to adhere to the oiledsurface. Hence the band is applied to the rings dry, and the strongconstriction of the cords compresses-it permanently, so closing thepores while the firmly adhering varnish covers and protects the entirejoint.

As the chief objects sought have been imperviousness and flexibility,and as the grain side of the leather oflers a smoother surface, andhence apparently one less likely to gather dust and impurities, it hashitherto been customary to attach the band in place with the grain sideoutermost, and to apply the oil to this side. To saturate the band withoil inthis way, has always been a long process, for obviously oil willnot go into a surface already impervious to gas except with extremeslowness. lit takes ordinarily from six weeks to two months to effectproper saturation, besides repeated applileather bands, the aggregatelosses due to the foregoing causes attain large figures, irrespective ofthose incident to the difliculties of re-oiling, or to the constantoversight which is required to prevent injury 'to the thin kid-likebands, should too long a time happen to elapse after the degree ofsaturation has fallen below proper limits. Where a meter is put in ahouse cellar, as it often is, near a furnace, the drying out of the thinleather if not properly saturated and so maintained is apt to be rapid,and thus local conditions may also complicate the difliculties ofkeeping the band in proper state. trouble can be efiiciently overcome bymaking the flexible wall of the bellows impervious to gas under pressureon its inner side, and spongy and hence absorptive of oil on its outerside. Then when the oil is applied to the spongy outer surface-even ifthe total thickness of the wall be very smalle-itwill be drawn bycapillary aflinity into the outer spongy stratum, and rapidly spreadthroughout the same, so that I have obtained even a better saturation ofthe band in thirty-six hours than I have hitherto got in six weeks. There-oiling can be made automatic by simply permitting the lower part ofthe band to dip in a quantity of oil I, placed in the bottom of themeter casing L, the new oil then being drawn into the spongy outer layerof the skin to replace whatever amount mayhave evaporated.

I may construct the flexible wall in accordance with the foregoingdescription in various ways-as, for example, by employing a materialspongy throughout and applying an inner impervious coating; but thesimplest and hence the preferable expedient is to attach the presentsheep-skin band to the diaphragm rings, so that the flesh side shall .beoutermost. The spongy layer on the flesh side, even of so thin a skin assheepskin, is quite absorptive enough when a good free-flowinglubricating oil is used, to become thoroughly saturated within the briefperiod before mentioned. The saturation I have discovered that all ofthiscan be somewhat hastened by encircling the flexible wall with astrip of material more absorptive than the spongy layer itselfsuch aslamp wick which will take up the oil rapidly and then deliver it to theband around the entire periphery of the latter. Two wicks may be used,as shown at J, K, Fig. 5, and held at the edges of the band in anysuitable way, as by the already present Wrapping cords. The wick in thiscase also bridges the joint at the ends of the band, so that the oilwill cross over the joint by the wick from one end of the band to theother, and not be stopped by the joint which, if securedby cement, mayact as a dam. If the encircling wick or wicks are not desired,'the jointcan be bridged by a short section M of wick or spongy leather laid incontact with the band and held by the cord on one side, as shown in Fig.4.

I claim:

-1. A dry gas meter, having a bellows comprising a flexible wall ofleather, with its flesh side outermost. Y

2. A dry gas meter, having a bellows comprising a flexible wall ofleather, with its flesh side outermost, and means for supplying oil'externally to said wall.

3. A dry gas meter, having a bellows comprising diaphragms, an annularband of leather secured at its edges to said diaphragms, with its fleshside outermost, means for uniting the ends of said band, and a bridgepiece of spongy flexible material secured to said band and extendingacross the joint at said ends.

at. A dry gas meter, having a bellows comprising diaphragms, an annularband of leather secured at its edges to. said diaphragms, with its fleshside outermost, means for uniting the ends of said band,

and a strip of spongy flexible material in with and encircling said bandand respec- I tively in proximity to the opposite edges thereof.

In testimony whereof I signature in presence of two witnesses.

LEWIS B. eawrnr.

Witnesses I GERTRUDE T. PORTER, MAY T. MCGARRY.

have afiixed my I

